Doug Fister is Still Due for a Regression to Mean

Last year’s trade of Doug Fister to the Tigers has become a point of contention for a lot of Mariners fans because the second Fister was traded—amidst the best season of his career—he got better.

But Fister is overdue for a regression that should make the trade look better for the Mariners.

Before the trade Fister was viewed basically as what he was: a league average pitcher. But Fister had posted very good results as a Mariner in 2011. His 3.33 ERA was great, and though his win-loss record didn’t reflect it, his process had improved, if only slightly. He was striking out more than an extra half-batter per nine innings, but he was also walking almost a half batter more while throwing less groundballs. He was in the second year of having a low HR/FB rate, which helped drive his results, but which could probably be sustained reasonably well in a park like Safeco that dampened home runs.

Fister’s xFIP with Seattle last year was 4.03, compared to 4.10 in 2010. FIP stands for fielding independent pitching, and factors only strikeouts, walks, and homeruns into its formulation. The reason that xFIP is better than FIP, and especially better than ERA, is that it uses a rudimentary process to normalize home run rates. By setting every pitcher’s HR/FB to 10 percent (approximately league average), and re-running the FIP formula with the new homerun total, xFIP creates a level playing field for pitchers in both hitters and pitchers parks.

But fly balls are only one of three kinds of batted balls. Grounders and line drives make up the other two, and both have a much greater effect on BABIP. Of all the batted types fly balls have the lowest batting average on balls in play, in part because home runs (which aren’t technically in play) aren’t counted toward the stat.

We often paint pitchers with a broad brush when it comes to luck. We see a guy who pitched with a .240 BABIP for a full season and say he was “lucky” (which seems like such a non-SABR term). We see a guy who pitched to a .340 BABIP and say he’s “unlucky.” But we also deal in terms of true talent.

True talent is when we believe that a player is able to perform above the league averages based on nothing immediately quantifiable, but because he has some sort of intrinsic talent that helps him buck the averages of the league. Before 2011, league perception of Fister was basically dead on. He was a league average pitcher who would miss very few bats, who would pitch to contact, but who figured to give up more ground balls than fly balls.

Line drives turn into hits at the highest rate, boasting a .696 BABIP, while grounders come in a .231. So the best way to get a base hit—big shocker here—is to hit line drives. The opposite applies for avoiding giving up base hits.

So when we see that Fister’s BABIP for 2011 was .272, we can go beyond comparing it to the league average of .291 by analyzing Fister’s batted ball breakdown.

AVG BABIP

AVG Rate

Fister Rate

Line Drives

.696

19.6

20.4

Grounders

.231

44.4

47.5

Fly Balls

.138

36.0

32.1

One of the major contributors to the perception of true talent is the ability for pitchers to prevent opposing hitters from squaring a ball up. Fister’s 20.4 line drive rate in 2011 was above a league average of 19.6. His groundball rate, which has an average BABIP of .231 but an ISO of .019—and thus is positive—was 47.5 percent.

So in the two highest contributors to BABIP, Fister’s rate was above league average. Basically, Fister’s batted ball type mean that he was more likely to give up hits more often than the average MLB pitcher. So his .272 BABIP was actually more lucky than we thought before. According to my simplified method of determining what Fister’s expected BABIP should be, which sets all of his batted ball types to league average BABIPs Fister’s BABIP should have been .296. Even worse for Fister, I didn’t have a league average BABIP for infield-flies, which is assuredly very low, but which make up about one third of all fly balls. Fister allows less infield fly balls than league average (6.9 percent compared to 10.6 percent).

There were 29 qualifying pitchers who had a higher line drive rate than Fister. Of those pitchers, only five had a BABIP below .272: Kyle Lohse, Josh Tomlin, Mike Leake, Joe Saunders, and Ian Kennedy. Of those pitchers, only Kennedy was worth more than 2.5 WAR (Lohse’s WAR), and much of that had to do with an xFIP that was driven down by averaging more than 8.0 K/9. The other four guys are below average at missing bats like Fister, with the highest K/9 of the group belonging to Leake (6.3 K/9).

Kennedy is considered good, but the rest certainly aren’t world beaters. Five guys are hardly a large enough sample to model a projected future path for Fister’s production, but if we use the 2011 guys that fit his profile as an example, but if you consider that of the other guys that fit Fister’s profile Lohse is the best, the trade figures to look better as time passes.